Presser mechanism for a warp knitting machine



Sept. 16,1969 K. KOHL PRESSER MECHANISM FOR A WARP KNITTING MACHINE 2 Sheets-Sheet 1 Filed March 9, 1967 INVENTOR. KARL KOHL BY Km AGENT Sept. 16,1969 K. KOHL 3,466,898

PRESSER MECHANISM FOR A WARP KNITTING MACHINE Filed March 9, 1967 2 Sheets-Sheet 2 INVENTOR KARL KOHL United States Patent 68,710 Int. Cl. D04b 23/00, 27/00, 15/28 U.S. C]. 66-86 7 Claims ABSTRACT OF THE DISCLOSURE Presser mechanism for a bearded-needle warp-knitting machine in which a presser plate is mounted on a rocker, the rocker is pivoted by means of a reciprocating push-rod connected to the rocker by a pivot pin eccentrically journaled in a bearing sleeve on the rocker, and the angular position of the bearing sleeve is varied to change the effective length of the push-rod during the reciprocating movement of the same, whereby engagement between the presser plate and the needle beards may be prevented although the push-rod reciprocates continuously CROSS REFERENCE TO RELATED APPLICATION This application is a continuation-in-part of my copending application Ser. No. 548,470, filed on May 9, 1966. and now abandoned.

BACKGROUND OF THE INVENTION This invention relates to warp knitting machines, and particularly to a mechanism for actuating the presser of the machine.

It is known to equip warp knitting machines with presser mechanisms which cause the presser to engage the beards of spring beard needles only in every second cycle of knitting movements. In one known arrangement, the presser plate is movably mounted on a rocker which is pivoted back and forth on the stationary machine frame by the main drive of the machine. The presser plate is shifted on the rocker by approximately the width of the hook-shaped end portion of the knitting needle in a d1rec tion away from the latter when engagement between the presser and the needle beard during rocker movement is to be avoided. The motion transmitting linkage which connects the presser plate to the main drive is complicated and subject to malfunctioning when not carefully maintained.

Another known arrangement includes cam drives for the needle bar, the yarn guide bar, and the sinker bar, which perform two operating cycles during each revolution of the main drive shaft, whereas the presser is actuated by a cam which as a single lobe on its circumference, whereby the presser is actuated only in every other knitting cycle. A knitting machine equipped with such an unbalanced presser mechanism is limited in its maximum operating speed.

The object of the invention is the provision of a presser mechanism which permits the presser to be inactivated during predetermined knitting cycles but which is simple in its structure and, therefore, more reliable in its operation than known devices of the first-described type, and which does not restrict the speed at which the knitting machine may be operated.

SUMMARY OF THE INVENTION The invention provides a control device which varies the effective length of the linkage connecting the drive 3,466,898 Patented Sept. 16, 1969 shaft to the rocker in synchronization with the movements of the knitting elements in such a manner that the stroke of the oscillating rocker movement may be modified.

Other features, additional objects, and many of the attendant advantages of this invention will be readily appreciated as the same becomes better understood by reference to the following detailed description of preferred embodiments, when considered in connection with the appended drawing.

BRIEF DESCRIPTION OF THE DRAWING In the drawing:

FIG. 1 shows a warp knitting machine equipped with a presser mechanism of the invention in fragmentary side elevation, and partly in section;

FIG. 2 shows a modified detail of the presser mechanism of FIG. 1 in a corresponding view; and

FIG. 3 shows the device of FIG. 2 and associated elements in fragmentary front elevation.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now to FIG. 1 of the drawing in detail, there is seen a needle bar 1 carrying spring beard needles 2 of which only one is visible. The knitting elements of the machine also include sinkers 3 and yarn guides 4. The knitting elements are driven in a conventional manner by non-illustrated cams fixedly mounted on a drive shaft 20, and by push rods.

A presser plate 5 is mounted on one end of a rocker 6 whose other end is pivotally supported on a shaft 7 which is an element of the stationary machine frame, not otherwise shown. The rocker is oscillated on the shaft 7 by a pushrod 8, and is connected with the pushrod by a thickwalled bearing sleeve 10 which is rotatable in a conforming cylindrical bore of the rocker 6, and whose axis is parallel to that of the shaft 7. An eccentric axial bore in the sleeve 10 rotatably receives a pivot pin 9 attached to the top end of the pushrod 8.

The pushrod 8 is an element of a linkage 19 which cooperates with a cam 21 on the shaft 20 for reciprocating the pin 9 in a generally vertical direction during rotation of the drive shaft 20. The sleeve 10 is connected with the drive shaft 20 by a motion transmitting train including a chain 11 trained over sprocket teeth on the sleeve 10 and over a double sprocket 12 coaxially rotatable on the shaft 7. Another chain 13 connects the sprocket 12 to a sprocket 14 on the output shaft of a clutch 15 whose input member is driven by the shaft 20 through a multiple speed transmission 16. A control member 17 on the clutch 15 permits the clutch to be disengaged, whereby the sleeve 10 is disconnected from the drive shaft 20,and a control lever 18 on the transmission 16 can be moved for selecting a desired transmission ratio.

When the transmission 16 is set for rotation of its nonillustrated output shaft at the same speed as that of the drive shaft 20, the sleeve 10 is rotated once during each revolution of the drive shaft. The initial angular position of the sleeve 10 then may be selected in such a manner that the pin 9 is in the illustrated retracting position while the linkage 19 engages one of the two lobes of the cam 21, whereby the presser plate 5 is unable to reach the knitting needles 2 more than once during each revolution of the drive shaft 20.

When the sleeve 10 is in a position offset from the illustrated position, while the linkage 19 cooperates with the other lobe of the cam 21, the presser engages the needle beards. The synchronization between the drive shaft 20 and the sleeve 10 may be modified by means of the control member '17 and the lever 18 in an obvious manner to produce a pattern in the knitted goods. A mechanical or electromechanical connection may be pro- 3. vided between the control member 17, the lever 18, and the non-illustrated main pattern mechanism of the knitting machine to vary the synchronization between the knitting elements 2, 3, 4 and the presser 6 in any desired manner.

FIGS. 2 and 3 show a modified apparatus for varying the effective length of the push-rod 8 in an apparatus which is otherwise substantially identical with that described above with reference to FIG. 1.

The eccentric sleeve 10 is turned during knitting by a chain trained over a sprocket 12' .on the shaft 7. A helical spring 22 whose ends are fastened to the circumference of the sprocket 12' and to the machine frame tends to turn the sprocket clockwise, as viewed in FIG. 2. A chain or other tension member 23 is fastened to the sprocket 12' and is trained over a portion of the sprocket circumference in such a manner that the sprocket is turned counterclockwise when the chain 23 is tensioned.

As is seen in FIG. 3, the chain 23 is also trained over a guide pulley 24, and its end remote from the sprocket 12 is attached to one arm of a lever 25 mounted on a fixed pivot 26. The other arm of the lever 25 carries a cam follower 27 which is held in engagement with the cam face of a pattern disc 28 by the spring 22. The pattern disc 28 is turned by the drive shaft 20' through a reducing gear transmission, not shown, similar to the transmission 16.

When the lever 25 is pivoted as it scans the cam face of the disc 28, the eccentric sleeve 10 is turned about its axis, the necessary torque being provided by the spring 22 or by the drive shaft which turns the disc 28 in a conventional manner, not further illustrated.

It should be understood, of course, that the foregoing disclosure relates only to a preferred embodiment of the invention, and it is intended to cover all changes and modifications of the example of the invention herein chosen for the purpose of the disclosure which do not constitute departures from the spirit and scope of the invention set forth in the appended claims.

What is claimed is: I

1. A presser mechanism for a warp knitting machine comprising, in combination:

(a) a rocker member;

(b) means for mounting said rocker member on a knitting machine for oscillating movement about an axis;

(c) a presser member mounted on a portion of said rocker member spaced from said axis;

(d) pushrod means having one end portion pivotally connected to said portion of said rocker member;

(e) drive means engaging another end portion of said pushrod means for reciprocating said pushrod means and for thereby oscillating said rocker member about said axis; and

(f) control means for varying the effective length of said pushrod means in synchronization with said reciprocating thereof by said drive means, and for thereby modifying one stroke of the oscillating movement of said rocker member, said control means including (1) first bearing means movable on said portion of said rocker member,

(2) second bearing means on said one end portion of said pushrod means, said first and second bearing having a common axis, and engaging each other for relative angular displacement about said axis and (3) shifting means for cyclically shifting said common axis relative to said second bearing means by moving said first bearing means on the rocker member.

2. A mechanism as set forth in claim 1, wherein one of said bearing means includes a pin member, and the other bearing means includes a sleeve member coaxially receiving said pin member, said pin member being mounted on said one end portion of said pushrod means, and said sleeve member being mounted on said portion of the rocker member, and said shifting means including means for angularly moving said pin member means about an axis spaced from said common axis.

3. A mechanism as set forth in claim 2, wherein said shifting means include motion transmitting means interposed between said drive means and said other bearing member for angularly moving the same While said drive means reciprocates said pushrod means.

4. A mechanism as set forth in claim 3, wherein said motion transmitting means includes clutch means, and means for disengaging said clutch means.

5. A mechanism as set forth in claim 3, wherein said motion transmitting means include a multiple-speed transmission, and means for varying the transmission ratio of said transmission.

6. A mechanism as set forth in claim 3, wherein said motion transmitting means include a cam member driven by said drive means and having a cam face; a cam follower member engageable with said cam face; yieldably resilient means holding said cam follower member in engagement with said cam face; and a tension member interposed between said cam follower member and said other bearing member.

7. A mechanism as set forth in claim 6, further comprising a wheel member mounted for rotation about the axis of oscillating movement of said rocker member; and an elongated drive member forming a closed loop and trained over said wheel member and said other bearing member, said yieldably resilient means being secured to said Wheel member for turning the same in one direction, said tension member being secured to said wheel member for turning the wheel member in the opposite direction when the tension member is tensioned during the engagement of said cam follower member with said cam face.

References Cited UNITED STATES PATENTS 2,699,052 1/ 1955 Zwingenberger 66-86 3,355,912 12/1967 Wenrich 66-86 WM. CARTER REYNOLDS, Primary Examiner US. Cl. X.R. 66-98 

